com.fusesource.forge.jmstest.probe.AbstractProbe.java Source code

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Here is the source code for com.fusesource.forge.jmstest.probe.AbstractProbe.java

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/*
 * Copyright (C) 2009, Progress Software Corporation and/or its
 * subsidiaries or affiliates.  All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.fusesource.forge.jmstest.probe;

import java.util.Observable;
import java.util.UUID;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.fusesource.forge.jmstest.probe.BenchmarkProbeValue.ValueType;

public abstract class AbstractProbe extends Observable implements Probe {

    private ProbeDescriptor descriptor = null;
    private String name;
    private boolean resetOnRead = false;
    private boolean active = true;
    private int inactiveAfterException = 5;
    protected long lastException = Long.MIN_VALUE;

    private Log log = null;

    public AbstractProbe() {
        this("Probe-" + UUID.randomUUID().toString());
    }

    public AbstractProbe(String name) {
        this.name = name;
    }

    public final BenchmarkProbeValue getProbeValue() {

        Number value = null;

        try {
            value = getValue();
        } catch (Exception e) {
            log().warn("Exception reading probe " + getDescriptor());
            lastException = System.currentTimeMillis();
            setActive(false);
        }

        BenchmarkProbeValue result = new BenchmarkProbeValue(getDescriptor(), System.currentTimeMillis() / 1000,
                value);

        if (isResetOnRead()) {
            reset();
        }
        return result;
    }

    protected abstract Number getValue() throws Exception;

    public void setName(String name) {
        this.name = name;
        descriptor = null;
    }

    public String getName() {
        return name;
    }

    public void setActive(boolean active) {
        this.active = active;
    }

    public boolean isActive() {
        if (active) {
            return true;
        } else {
            if (System.currentTimeMillis() - lastException > getInactiveAfterException() * 1000L) {
                setActive(true);
                return true;
            } else {
                return false;
            }
        }
    }

    public int getInactiveAfterException() {
        return inactiveAfterException;
    }

    public void setInactiveAfterException(int inactiveAfterException) {
        this.inactiveAfterException = inactiveAfterException;
    }

    public boolean isResetOnRead() {
        return resetOnRead;
    }

    public void setResetOnRead(boolean resetOnRead) {
        this.resetOnRead = resetOnRead;
    }

    public void reset() {
    }

    public BenchmarkProbeValue.ValueType getValueType() {
        return ValueType.GAUGE;
    }

    public ProbeDescriptor getDescriptor() {
        if (descriptor == null) {
            descriptor = new ProbeDescriptor(this);
        }
        return descriptor;
    }

    public void probe() {
        BenchmarkProbeValue value = getProbeValue();
        log().debug("Probe: " + getName() + "=" + value);
        setChanged();
        notifyObservers(value);
    }

    private Log log() {
        if (log == null) {
            log = LogFactory.getLog(this.getClass());
        }
        return log;
    }
}